I need to know the exact RPM's for a stock LT-Z400
Also would be nice to know the RPM's with the following mods:
K&N, w/ pro flow adapter and outer wear, jet kit, no air box lid.
And a Yosh. slip on RS3.

 

Stock rev limit is bout 8500 and it will be the same after all the mods too. You have to replace the CDI which controls the limiter to increase your rev limit. I am going with a Vortex programable that will up it to about 10,500 or 11k

 

How much does the Vortex cost?
To me 10-11k seems a bit risky might blow the motor, but I don't really know.

 

The thing is that the DRZ motor in the dirtbikes rev limit was about 10k and they ran just fine they wanted to de-tune the quads for some odd reason. That is why you see people using the DRZe base gasket and other things from that motor. 10k would be fine. I think the vortex is about 400 but there is a switch that you install that you can switch from torque to top end because it also controls the timing curve. If you search around the dyna and the yoshi CDI's are also really good. There are also many sites that sell rev boxes that will increase your rev limit by 1k or 2k...

 

I mean just think about the extra power I could get out just looking at this dyno sheet...

here

 

1k+cdi on a stock motor will be fine.going with a 10k-11k with a stock motor is going to be a waste of money with the stock cams in.if you do put cams in and go with the 10k-11k cdi you need to put the drz-e springs in or white- bro kibble white springs in .turning those high rpms with the stock springs you will float a valve and thats not going to be good